2001 Suzuki Katana 600 motorcycle won't start

Question

A few months ago I bought a used 2001 Suzuki Katana 600 with about 11,000 miles on it. I rode it without any issues for the first month or so. After that I started having occasional issues with starting it up.

The first few times button start would not work instantly. I would have to re-try a couple times before the motorbike started up.

Then a couple times button start did not work even after a few attempts. Push starting, however, worked.

Note that in between these isolated incidents button start would work normally -- that is, at the first attempt.

Finally, a couple of days ago, after not having ridden the motorbike for nearly three weeks, I tried starting it up. Button start did not work, even after several attempts, and neither did push start. I checked the voltage across the battery terminals and it read approximately 10.5V. So I bought a trickle charger and hooked it up. Five hours later, still no luck. So I took the battery to a mechanic for a load test and the mechanic said it was fine.

I suspect the starter motor but I hear it whirring each time I press the button (as opposed to hearing just a clicking sound); it just doesn't start the engine. One thing to note is that if I keep trying the button start the start motor whirrs slower on each attempt. Eventually it grinds to a halt. Then if I let the motorcycle "rest" for a couple of hours and try again, its the same cycle all over again.

What else could be wrong?

I have dropped off the motorbike with the mechanic but I am new to motorcycles and don't want to be taken for a ride (pun not intended) by the mechanic. At best I would like to do the repairs myself so I can learn more about my motorcycle and save on labor costs but even if I have to pay a mechanic to fix the problem I would like to go in prepared with knowledge of possible problems.

Thank you!

Answer 1

If the voltage was 10.5V that means the battery was completely empty, 0%. You should never let your battery go that low, several such discharges damage it irreversibly. I assume it is a lead-acid battery? Best never let it go below 12V (I mean voltage measured after the battery has been at rest - not powering anything, nor charged - for a few hours).

If you discharged your battery that low, 5 hours is nowhere near enough to charge it, it will take at least 24 hours to charge it, if not more. Charge it until the voltage measured on the battery while it is being charged is at least 14.4V, and then a few hours more at that voltage (try to keep it constant, decrease the current if needed). Charge it with a 0.1C current (with current in amperes of 1/10 of the battery capacity in Ah, so for a 45Ah battery that would be 4.5A), or lower. Fast charging with higher amperage only gives surface charge, which will be gone quickly under load. After charging it completely you might try charging it with higher voltage (15.5-16.0V) for a few hours to try to recover a bit of the sulphation damage that you've done with the 10.5V discharge. But do that carefully (no sparks) and don't leave it charging unattended, as explosive hydrogen might be emitted from the battery.

Other than that it might be that the starter brushes have worn out - these need to be replaced from time to time. Try hitting the starter with a hammer hard a few times before trying to start - if that helps temporarily (for 1 start), it means that replacing the brushes will fix it permanently.

You might want to borrow a known-good battery, charge it completely, so it reads over 12.5V after a few hours rest, and try to start it with that battery - so you'll know if that is the problem - but I suspect it is. Or brushes. Or probably both.

Answer 2

This may sound obvious but is there water in the tank? I've been through this a few times with different bikes - the bikes can work for a while until the ratio of water is just to great for the engine to start. If the bike has carburetors, start by draining the bowls.

I also have had problems with a dead battery. As miernik said, they must be kept at top charge via a trickle charger when not in use. In my case, my last battery lasted barely a year even though I use the bike 2 or 3 times a week.

Answer 3

I have a Suzuki Katana that was having the same problem. It would cut out at the stop light or wouldn't start at times. I checked plugs, wires, and fuel. It turned out to be just a defective battery. Now she runs like brand new! PS: Get the expensive battery with high amperage because Katana's are picky when it comes to the power supply. Duralast batteries are good.